[U-Boot] u-boot:arm:Boot MLO and U-boot img from nand flash for omap4460

Hi , i interfaced nand flash-(MT29F4G08ABBDAH4-IT) with omap4460. I able to boot uboot and kernel from SD Card. Now, i want boot uboot and kernel from Nand Flash. for that purpose,i copied MLO and u-boot image to Nand partition. but problem is,if i tried boot from nand,it shows that MLO is unknown image type. without sd card ,i am not able to boot from nand. as concern of hardware, processor tries to fetch instruction from nand ,verify using CRO. i want to know. that in which file, i have to change or config for booting for nand. plz help me..